Cah. Biol. Mar. (1999) 40 : 135-140 Present day distribution and historical biogeography of the tribe Ophidiini (Ophidiiformes, Ophidiidae, Ophidiinae) from the East Tropical Atlantic (CLOFETA area) and North-East Atlantic and Mediterranean (CLOFNAM area) Jesus MATALLANAS1, and Margarida CASADEVALL2 1 Unitat de Zoologia, Dept. Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain 2 Corresponding author: M. Casadevall, Unitat de Biologia Animal, Dept. Ciències Ambientals, Universitat de Girona, Campus de Montilivi s/n, 17071 Girona, Spain Fax: (34) 972 418150; e-mail: [email protected] Abstract: The present day geographic distribution of the Ophidiini tribe (Ophidiidae, Ophidiinae) in the Clofnam (North- Eastern Atlantic and Mediterranean) and Clofeta (Eastern Tropical Atlantic) areas is revised in this paper. Results show that Parohidion vassali is not a Mediterranean endemic species, and the presence of Ophidion barbatum in the Atlantic is confirmed. Moreover, the paper tries to analyse the historical events which could have caused the present situation of two genera, Ophidion and Parophidion, both in the Atlantic and in the Mediterranean. Although first fossil records of Ophidion and Parophidion date from the Pliocene, when considering all the historical events occurred from the existence of the Tethys Sea to the opening of the Atlantic and the Mediterranean formation, a much earlier origin of these genera seems to be more likely. The situation of Ophidion barbatum and O. rochei in the Mediterranean and Black Sea is also discussed. Résumé : Distribution actuelle et biogéographie historique de la tribu des Ophidiini (Ophidiiformes, Ophidiidae, Ophidiinae) de l'Atlantique oriental tropical (aire CLOFETA), de l'Atlantique Nord-Est et de la Méditerranée (aire CLOFNAM). La distribution géographique actuelle de la tribu des Ophidiini (Ophidiidae, Ophidiinae) dans les aires du Clofnam (Atlantique du Nord-Est et Méditerranée) et Clofeta (Atlantique Est tropical) est révisée. Nos résultats vont à l’encontre de l’endémicité de Parophidion vassali en Méditerranée et confirment la présence d’Ophidion barbatum dans l’Océan Atlantique. De plus, ce travail essaie d’analyser les événements historiques qui pourraient expliquer la situation actuelle des deux genres, Ophidion et Parophidion, à la fois dans l’Atlantique et en Méditerranée. Bien que les premiers fossiles d’Ophidion et Parophidion aient été datés du Pliocène, l’ensemble des événements historiques depuis l’existence de la Mer Tethys jusqu’à l’ouverture de l’Atlantique et la formation de la Méditerranée, suggèrent une origine beaucoup plus ancien- ne des deux genres. La situation d’Ophidion barbatum et d’O. rochei en Méditerranée et en Mer Noire est aussi discutée. Keywords: Ophidiinae, Ophidion, Parophidion, distribution, historical events. Introduction species. According to Cohen & Nielsen (1978), there are so many species and so little information on their anatomy that The Ophidiiform order is a highly diverse group of several years may pass before a well documented study of approximately 135 genera and between 300 and 400 their systematics appears. In this paper, the Ophidiiformes classification proposed Reçu le 8 décembre 1998; accepté après révision le 5 mars 1999. by Cohen & Nielsen (1978) and accepted, in general trends, Received 8 December 1998; accepted in revised form 5 March 1999. by Schwarzhans (1980), Gordon (1982) and Gordon et al. 136 OPHIIDIINI DISTRIBUTION (1984), is followed. According to these scientists, the Ophidion rochei: specimens from our collection Ophidiinae are one of the four subfamilies of the (Universitat Autònoma de Barcelona and Universitat de Ophidiidae. Girona) from the Western Mediterranean. Nolf & Steurbaut (1989) stated that the Ophidiinae have Ophidion lozanoi: Holotype (138 mm SL, Institut de existed in neritic deposits since the Eocene; Lepophidium Ciències del Mar, Barcelona, Spain, N° 409/1983) off the appeared in the lower Oligocene and Ophidion in the lower Saharan coasts; Paratype (130 mm SL, Station Marine, Pliocene. Now, according to Lea (1980), the Ophidiinae IFAN - Gorée, Senegal, N° 59.684) off Dakar. have a circumtropical and temperate distribution in the continental slope in the world ocean. Results and Discussion The group has recently been revised by Lea (1980) in the Eastern Pacific Ocean; by Gordon (1982) in the Eastern I. Present day distribution Gulf of Mexico; by Nielsen (1986) in the Clofnam area and by Nielsen (1991) in the Clofeta area. 1) Parophidion vassali The Ophidiinae are highly concentrated on both sides of According to Nielsen (1986), this species, apparently America, in tropical and temperate waters. In contrast, until considered as a Mediterranean relict (Lea, 1980), is found in now, only the following species have been assigned to the the Western Mediterranean, from Gibraltar to the Adriatic Clofnam area: Parophidion vassali (Risso, 1810), Ophidion sea. Fischer et al. (1987) extend its distribution area to the barbatum Linnaeus, 1758 and O. rochei Müller, 1845. In the Eastern Mediterranean. Matallanas & Casadevall (1990) found it in Madeira (six specimens) and, on the basis of a Clofeta area, Nielsen (1991) only recorded Ophidion figure that Cadenat (1950) ascribes wrongly to Ophidion barbatum and Genypterus capensis (Smith, 1847). barbatum, they postulate its presence on Senegal coasts. O. lozanoi Matallanas, 1990 has also to be included in this Finally, Azevedo and Heemstra (1995) have recorded this area. species in the Azores. Ophidiinae are divided in two tribes: Lepophidiini and Ophidiini. The latter includes five genera: Parophidion, We have recently studied a specimen captured by the Raneya, Chilara, Otophidium and Ophidion. Between them, Discovery in the Canary Islands, and its proximity to only Ophidion and Parophidion genera have been assigned, African coasts supports the possibility of finding P. vassali until now, to the Clofnam and Clofeta areas. along the whole NW African coast. Actually, A. Brito The present study has been induced by the incomplete (pers. com.) has caught specimens of P. vassali in the knowledge (only two partial synopsis given by Nielsen, Canary Islands at a depth between 4 and 20 meters. The 1981, 1991) of the Ophidiinae from the Central East presence of this species in the Clofeta area has not yet been Atlantic, including the Madeira and Canary Archipelagos recorded by Nielsen (1991). and also the Senegal coasts. The objectives are to revise the 2) Ophidion barbatum and O. rochei present day distribution of Ophidion and Parophidion These two species have often been confused with each genera in the Clofeta and Clofnam areas and also to try to other. A recent paper of Casadevall et al. (1996b) has shown analyse the historical events which may have caused the a wide variety of morphometric, meristic and anatomical amphioceanic distribution of these two genera. differential characters. We want to emphasize the possession of such a high number of non-overlapping characters when, according to Gordon et al. (1984), in Material examined Ophidiiformes, meristic and morphometric data show a broad range of overlapping between several species. Parophidion vassali: eight specimens (seven from Madeira Moreover, their habitat, sex-ratio and maximum length in and one from Canary Islands) from the “Museu Municipal the western Mediterranean are also different (Matallanas & do Funchal” (Madeira, Portugal). Riba, 1980), and the same will be quoted in relation to its Ophidion barbatum: three uncatalogued specimens from feeding habits (Matallanas, 1980 and 1981). the Canary Islands (Departamento de Zoología, Ciencias For Tortonese (1975) and Bauchot & Pras (1980) the Marinas, Universidad de la Laguna, Islas Canarias, Spain), presence of O. barbatum in the NE Atlantic is doubtful. some uncatalogued specimens from the Saharan coasts However, for Nielsen (1986, 1991) the distribution of this (Institut de Ciències del Mar, Barcelona, Spain), one species is “Western Mediterranean, from Gibraltar to the uncatalogued specimen from the Gulf of Cádiz (Instituto de Adriatic and Eastern Atlantic from Southern England to Ciencias Marinas de Andalucía, Puerto Real, Cádiz, Spain) Senegal”. and specimens from our collection (Universitat Autònoma We have studied specimens of O. barbatum from the de Barcelona and Universitat de Girona) from the Western Canary Islands, Senegal, Saharan coasts and from the Gulf Mediterranean. of Cádiz, which confirms its Atlantic distribution. J. MATALLANAS, M. CASADEVALL 137 In contrast, O. rochei seems to be confined to the formation of the Mediterranean; this isthmus then Mediterranean, Adriatic and Black Sea (Fischer et al., submerged until the Pliocene when it re-emerged 1987). permanently. Submergence facilitates faunal exchange between eastern Pacific and the Caribbean in the two ways. 3) Ophidion lozanoi For White (op.cit.), for example, the submergence of the Is another species of Ophidiinae recently described isthmian link between North and South America allowed (Matallanas, 1990) from NW African specimens. This westward dispersal of the Caribbean lineage of the species has four gillrakers, 24-26 pectoral fin rays, palatine Atheriniform subfamily Atherinopsinae, back into the teeth in four rows and the rostral spine larger than the one of Pacific, and a similar pattern was observed by Howes (1991) O. barbatum. O. lozanoi is also probably distributed in the with the Merlucciidae. SW Mediterranean since Dieuzeide et al. (1955) mentioned